We have developed a rapid magnetic resonance imaging (MRI) study of the lumbar spine that can be performed using nearly all clinical MRI scanners. Because the total imaging time is only approximately 2 minutes, the rapid MRI is cost competitive with plain films. Thus, it has the potential for playing a major role in the diagnosis and subsequent treatment of patients with low back pain. Our goal is to examine the consequences of substituting the rapid magnetic resonance (MR) scan for plain film x-rays as the initial imaging examination in patients with low back pain. We will test the hypothesis that substituting a rapid MRI for plain films will not only result in better patient outcomes, but will also be more cost-effective. Using a rapid MRI early in the care of patients with low back pain might benefit patients by: 1) providing a more rapid definitive diagnosis; 2) obviating further imaging or referral; and 3) reassuring both patient and physician that there is no serious disease. There is a risk that the incidental abnormalities commonly seen on lumbar spine MRI might lead to unnecessary diagnostic and therapeutic interventions that otherwise would not have been performed, resulting in both worse patient outcomes and higher costs. Evaluating these competing possibilities requires measuring actual patient outcomes, and not merely image quality or diagnostic accuracy. To test our hypothesis, we will recruit 372 patients with low back pain for whom plain x-rays have been requested, and randomly assign them to receive either plain films or the rapid MRI. Patients will then be followed for 12 months to ascertain clinical outcome and patient satisfaction, impact on diagnostic and therapeutic decision-making, and utilization of resources. Estimates of the total annual direct and indirect costs attributable to low back pain in the U.S. approach 50 billion dollars. Even if the rapid MRI saves only 1 percent of only the direct medical costs, this translates into 240 million dollars/year. It is likely that use of the rapid lumbar MRI will increase over the next several years. Our goal is to evaluate the practical and realistic consequences of replacing lumbar spine x-rays with this promising new technology. We have a window of opportunity before the rapid MRI becomes widely disseminated and a randomized trial is made impossible by the expectations of both patients and physicians.